Image capture system having virtual camera

ABSTRACT

An improved image capture system capable of combining the individual images from at least two image capture devices to produce a virtual camera for simulated line-of-sight image capture in such computer-based image capture applications as video conferencing, video telephony, video messaging, video postcards, multimedia training, and/or multimedia authoring.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of photographicand/or video image capture systems and, more particularly, to animproved image capture system capable of combining the individual imagesfrom at least two image capture devices to produce a virtual camera forsimulated line-of-sight image capture.

2. Description of the Related Art

A fundamental challenge in photographic and/or video image capture isensuring that the image capture device and subject are properlystationed to provide line-of-sight image capture. As used herein, theterm “line-of-sight image capture” means capturing a photographic and/orvideo image while the subject is looking directly into the lens of theimage capture device. Line-of-sight image capture is desirable in thatthe resulting photographic and/or video images show the subject lookingoutward toward a viewer for simulated face-to-face contact. Ifline-of-sight image capture is not performed, the subject has theappearance of staring off away from the viewer which, as will beappreciated, diminishes the intimacy associated with face-to-facecontact.

Line-of-sight image capture involves two basic operations. First, theimage capture device and the subject must be positioned such that thesubject is disposed within the field of view of the image capturedevice. This may be accomplished by adjusting the position of thesubject and/or image capture device while monitoring the position of thesubject through the use of a viewfinder or preview window. Second, thesubject must look directly into the lens of the image capture deviceduring image capture. The end result is a photographic and/or videoimage which depicts the subject looking directly outward for simulatedface-to-face contact with a viewer.

Line-of-sight image capture is not particularly difficult whenendeavoring to capture the photographic and/or video image of anotherperson. An operator can simply view the subject within the viewfinder,adjust the image capture device and/or the positioning of the subject toensure that the subject is within the viewing angle of the lens, andthen instruct the subject to look into the lens before activating theimage capture device. Unique challenges exist, however, when theoperator of the image capture device is desirous of capturing his or herown photographic and/or video image. For example, in the photographiccontext, it may be difficult for the operator to ensure that they areproperly disposed within the viewing angle of the image capture device.The operator may attempt to take his or her own photographic image byholding a photographic image capture device at arms length and pointingit back at himself or herself. This may be problematic, however, in thatthe operator is incapable of previewing their own image because theviewfinder is located on the opposite side of the photographic imagecapture device.

This problem has been overcome in the video camcorder context with theadvent of viewfinders that may be selectively positioned in the samedirection as the lens to allow operators to view themselves whilecapturing their own video image. Notwithstanding this improvement,line-of-sight image capture is nonetheless difficult to perform becausethe operator must, by definition, look away from the lens of the imagecapture device in order to preview their image in the viewfinder. If theoperator performs image capture while looking at the viewfinder, theywill appear to be staring off away from a viewer. If the operator looksback to the lens prior to performing image capture, they run the risk ofinadvertently moving the position of the lens such that the resultingimages are not centered within the field of view.

Computer-based image capture systems suffer similar drawbacks inperforming line-of-sight image capture. Computer-based image capturesystems may include, for example, video conferencing systems, videotelephony systems, video messaging systems, video postcard systems,multimedia training systems, and multimedia authoring systems. At aminimum, such systems include a display for visually communicatinggraphical and/or textual information to an operator, an image capturedevice for capturing the photographic and/or video image of theoperator, and a computer processing unit for coordinating the operationof the overall system. The image capture device is disposed at apredetermined location about the periphery of the display such that theoperator has an unobstructed view of the display.

The main obstacle in performing line-of-sight image capture in suchcomputer-based image capture systems stems from the physical distance oroffset between the image capture device and the display. Morespecifically, line-of-sight image capture in computer-based imagecapture systems can only be conducted at the expense of viewing theinformation on the display. This may be seen, for example, withreference to the prior art desktop video conferencing station 2 shown inFIG. 1. The video conferencing station 2 comprises a video display 4, animage capture device 6, and a personal computer 8. The image capturedevice 6 is disposed on top of the video display 4 to ensure that thelocal conferencee 10 has an unobstructed view of the information on thedisplay 4. This necessarily produces a vertical offset between the imagecapture device 6 and the local conferencee 10 such that, when looking atthe display 4 as at 12, the local conferencee 10 appears to be lookingaway from the image capture device 6 from the vantage of the remoteconferencee. In order to establish face-to-face contact with the remoteconferencee, the local conferencee 10 must look directly into the lensof the image capture device 6 as at 14. This disadvantageously restrictsthe local conferencee's 10 ability to view the information displayed onthe display 4.

Although described above in the context of a video conferencing system,it is to be understood that this problem exists in every computer-basedapplication where an operator wants to capture his or her own image.These applications may include, but are not necessarily limited to,video conferencing, video telephony, video messaging, video postcard,multimedia training, and multimedia authoring.

The present invention is directed at overcoming, or at least reducingthe effects of, one or more of the problems set forth above.

SUMMARY OF THE INVENTION

In one aspect of the present invention, an apparatus is providedincluding display means, image capture means, and means for seamlesslycombining images obtained from the image capture means. The displaymeans is provided for displaying information to an operator. The imagecapture means is disposed proximate to the display means and providedfor capturing a first and second image of the operator from first andsecond offset locations. The means for seamlessly combining the firstand second images from the image capture means forms a virtual camera ata predetermined location on the display for simulating line-of-sightimage capture of the operator.

In another aspect of the present invention, an apparatus for simulatingline-of-sight image capture. The apparatus includes display means, imagecapture means, and image correlator means for combining the imagesobtained from the image capture means. The display means is provided fordisplaying information to an operator. The image capture means isdisposed proximate to the display means and provided for capturing afirst and second image of the conferencee from first and second offsetlocations. The image correlator means is provided for receiving andcombining the first and second images of the operator to form acomposite image depicting the operator looking substantially directlyinto a lens of an image capture device.

In a still further aspect of the present invention, a method is providedfor simulating line-of-sight image capture within a computer-based imagecapture system. The method comprises the steps of: (a) capturing a firstimage of an object from a first predetermined location; (b) capturing asecond image of the object from a second predetermined location; (c)combining the first and second images of the object to form a compositeimage depicting the object looking directly into a lens of an imagecapture device.

In yet another aspect of the present invention, an apparatus is providedfor facilitating face-to-face communications between conferencees atremote locations. The apparatus includes at least two conferencingstations communicatively linked together. Each conferencing stationincludes display means, image capture means, and means for combiningimages from the image capture means. The display means is provided fordisplaying information to a conferencee. The image capture means isprovided for capturing images of the conferencee from at least twodifferent offset locations. The means for combining the images capturedby the image capture means forms a virtual camera at a predeterminedlocation on the display means for simulating face-to-face communicationbetween conferencees at remote video conferencing locations.

In a still further aspect of the present invention, a method is providedfor facilitating face-to-face communication between a first being and asecond being. The method comprises the steps of: (a) capturing twoimages of a first being from offset points of view; (b) combining theimages to form a composite image depicting the first being lookingsubstantially directly into the lens of an image capture device; and (c)communicating the composite image of the first being to a second being.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIG. 1 is a side view of a video conferencing station of the prior art;

FIG. 2 is a flow chart illustrating a method of accomplishingline-of-sight image capture in a computer-based image capture system inaccordance with the present invention;

FIG. 3 is a block diagram illustrating the basic functional elements ofan improved video conferencing system of the present invention;

FIG. 4 is an elevational view illustrating the field-of-view for each ofa pair of co-aligned video cameras in accordance with the presentinvention;

FIG. 5 is an elevational view illustrating the field-of-view of a videocamera as employed in prior art video conferencing systems;

FIG. 6 is a front elevational view illustrating the manner in which acomposite video image formed in accordance with the present inventionmay be stretched from a first state to a second state to remove parallaxdistortions;

FIG. 7 is a perspective view of a video conferencing station of a firstembodiment of the present invention;

FIG. 8 is a perspective view of a video conferencing station of a secondembodiment of the present invention;

FIG. 9 is a side view of the video conferencing station shown in FIG. 8;

FIG. 10 is a perspective view of a video conferencing station of a thirdembodiment of the present invention;

FIG. 11 is a perspective view of a video conferencing station of afourth embodiment of the present invention;

FIG. 12 is a top view of the video conferencing station shown in FIG.11;

FIG. 13 is a perspective view of a video conferencing station of a fifthembodiment of the present invention; and

FIG. 14 is a perspective view of a video conferencing station of a sixthembodiment of the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Illustrative embodiments of the invention are described below. In theinterest of clarity, not all features of an actual implementation aredescribed in this specification. It will of course be appreciated thatin the development of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure.

With reference to FIG. 2, shown is a flow chart illustrating a method 16of accomplishing line-of-sight image capture in a computer-based imagecapture system in accordance with the present invention. Theline-of-sight image capture method 16 finds particular application incomputer-based image capture systems where the operator wants to capturehis or her own photographic and/or video image. By way of example, suchcomputer-based image capture systems may include, but are notnecessarily limited to, video conferencing systems, video telephonysystems, video messaging systems, video postcard systems, multimediatraining systems, and multimedia authoring systems.

The first step 18 involves capturing a first image of the operator froma first predetermined location about the periphery of the display of thecomputer-based image capture system. The second step 20 involvescapturing a second image of the operator from a second predeterminedlocation about the periphery of the display of the computer-based imagecapture system. In an important aspect of the present invention, steps18 and 20 are accomplished by providing at least two image capturedevices about the periphery of the display of the computer-based imagecapture system. Disposing the image capture devices about the peripheryof the display is necessary to ensure that the operator has, at alltimes, an unobstructed view of the visual communication on the display.The image capture in steps 18 and 20 should preferably occursimultaneously so as to obtain images of the operator from at least twodifferent perspectives at a particular point in time.

The images captured in steps 18 and 20 are then combined in step 22 toform a virtual camera at a predetermined location on the display of thecomputer-based image capture system. By this, it is meant that theindividual images obtained in steps 18 and 20 are combined in such afashion that the resulting composite image appears to have been obtainedfrom a single image capture device having a lens disposed on the surfaceof the display pointing at the operator for line-of-sight image capture.This is referred to as a “virtual camera” because the desiredline-of-sight image capture is simulated by combining the individualimages such that it appears as though it was captured from a singlepoint on the display, rather than through the use of an actual imagecapture device located within the perimeter of the display.

Step 24 involves displaying the composite image obtained in step 22 onthe local display or a remotely located display. Projecting thecomposite image from step 22 onto the local display may be helpful insituations where the operator wishes to preview their own image, such asduring video messaging, creating video postcards, multimedia training,and multimedia authoring. Projecting the composite image from step 22onto a remotely located display may be helpful in situations where theoperator wishes to transmit their image to a person at a remotelocation, such as during video conferencing and video telephony. Ineither case, the operator will appear to be looking directly outwardfrom the composite image for simulated face-to-face contact with aviewer. In a preferred embodiment, the composite image should beprojected onto the local or remote display such that it appears in thesame approximate position as the virtual camera. Co-aligning thecomposite image and the virtual camera in this fashion providessimulated line-of-sight image capture without causing the operator toremove his or her eyes from the display to look into an image capturedevice.

The advantages and benefits of performing line-of-sight image capture incomputer-based image capture systems in accordance with the presentinvention will be discussed below within the context of a videoconferencing system. It is to be readily understood that the followingembodiments are set forth by way of example only and not limitation. Themethod 16 of the present invention, once again, may find application inany computer-based image capture system where the operator wants tocapture his or her own photographic and/or video image. In addition to avideo conferencing system, these computer-based image capture systemsmay include, but are not necessarily limited to, video telephonysystems, video messaging systems, video postcard systems, multimediatraining systems, and multimedia authoring systems.

With reference to FIG. 3, shown is a block diagram of an improved videoconferencing system 30 provided in accordance with the presentinvention. Broadly stated, the improved video conferencing system 30includes a plurality of individual video conferencing stations 32interconnected via a communication link 34 for facilitating the exchangeof audio and video information between remote conferencees 36. Eachvideo conferencing station 32 includes a control module 38, a videomonitor 40, and at least two video cameras 42, 44. The video cameras 42,44 are disposed on opposite sides of the video monitor 40 for obtainingvideo images of the local conferencee 36 from at least two differentvantage points.

In one aspect of the present invention, the control module 38 of eachvideo conferencing station 32 seamlessly combines the video imagescaptured by the local video cameras 42, 44 to produce a single compositevideo image that depicts the local conferencee 36 appearing to lookdirectly into a camera located on the screen of the local video monitor40 (a “virtual camera”). Thus, when the composite video image producedby the local control module 38 is transferred to the video monitor 40 ofa remote video conferencing station 32, the image displayed on theremote video monitor 40 appears to be looking directly at the remoteconferencee 36. In this fashion, the conferencees 36 can view theirlocal video monitors 40 while maintaining the outward appearance oflooking directly into a camera for effective face-to-face contactbetween the conferencees 36.

The control module 38 includes a central processing unit (CPU) 46, avideo graphics card 48, and one or more video capture devices 50, 52.The CPU 46 manages the overall operation and interaction between thevideo graphics card 48, the video capture devices 50, 52, the videomonitor 40, and the video cameras 42, 44. The video graphics card 48facilitates the transmission of video information from the CPU 46 to thevideo monitor 40. The video images obtained by the video cameras 42, 44are transferred to the local CPU 46 via the video capture devices 50,52. In one embodiment, application and/or driver code within the CPU 46is programmed to carry out the operation of seamlessly combining thevideo images from each video camera 42, 44 to form the single compositevideo image of the local conferencee 36.

The algorithm employed by the CPU 46 to seamlessly combine theindividual images may be based on any of a variety of well known imagecorrelation techniques, such as described in Digital Image Processing,2nd Edition, William K. Pratt (1991), the entire contents of which isincorporated herein by reference. Generally speaking, image correlationinvolves conducting a pixel-by-pixel comparison of two video images todetermine the spatial differences between the images and thereby correctfor any perspective view differences between the individual images. Byseamlessly combining the individual video images in this fashion, theCPU 46 effectively shifts the point of view of each video camera 42, 44from the perimeter of the video monitor 40 toward a predeterminedlocation on the display of the local video monitor 40. This inwardshifting continues until the point of view of each video camera 42, 44effectively converges to form a single, virtual point of view at apredetermined position on the display of the local video monitor 40.

This virtual point of view, or virtual camera, is advantageous becauseit creates the impression that the local conferencee is looking directlyinto an actual camera. As viewed by a remote conferencee 36, it appearsas though the local conferencee 36 is looking directly out of the videomonitor 40 for simulated face-to-face contact. By forming the virtualcamera on the display of the local video monitor 40, the localconferencee 36 can continuously view the information on their videomonitor 40 without having to look at the video cameras 42, 44 toestablish eye contact with the remote conferencees 36.

The video conferencing system 30 of the present invention may beconstructed from any of a variety of commercially available components.For example, the central processing unit (CPU) 46 may comprise anynumber of processing units capable of high speed parallel operations,such as the PENTIUM®, PENTIUM PRO®, and other processors based on theMMX technology developed by the Intel Corporation. The video graphicscard 48 may similarly comprise any number of different commerciallyavailable video graphics cards, but in one embodiment is a devicecontrolled interface (DCI) enabled for stretching the composite videoimage on the video monitor 40 for the purpose of removing parallaxdistortions. The video capture devices 50, 52 may comprise any number ofoff-the-shelf video capture devices capable of converting the analogvideo images from the video cameras 42, 44 into digital datarepresentative of the analog video images. For example, the videocapture devices 50, 52 may include, but are not necessarily limted to,any of a variety of commercially available video cards, such as theISVR3 video capture card available from Intel Corporation, and any of avariety of commercially available cameras having video capturecapability, such as the QuickCam™ and QuickClip™ cameras available fromthe Connectix Corporation.

Although shown as two discrete components, it is to be readilyunderstood that the video capture devices 50, 52 may be replaced with asingle video capture card having two channels. The video monitor 40 mayinclude any number of different off-the-shelf monitors, including butnot limited to a standard VGA computer monitor or a NTSC television set.The video cameras 42, 44 may similarly comprise any of a variety ofcommercially available image capture devices capable of generating videoand/or photographic output. The communication link 34 may include any ofa variety of communication interfaces that meet Internet andtelecommunications industry standards (i.e. H. 320, H. 323, H. 324),such as an ISDN interface to a local telephone carrier or a local areanetwork (LAN) interface card to a local area network. Constructing theimproved video conferencing system 30 from off-the-shelf components inthis fashion advantageously minimizes production cost.

The video conferencing system 30 of the present invention is capable ofhandling both close and long range video conferencing scenarios byproviding the ability to selectively modify the aspect ratio of thevirtual camera. As shown in FIG. 4, the video cameras 42, 44 of thepresent invention are disposed on either side of the video monitor 40such that each field-of-view 54, 56 overlaps before enveloping theconferencee 36. The point where the two fields-of-view 54, 56 intersectis denoted generally at 58. The area located between this intersectionpoint 58 and the video cameras 42, 44 is referred to as the dead zonebecause the CPU 46 is incapable of producing a composite video image inaccordance with the present invention when the conferencee 36 is locatedin this area. All points past the intersection point 58 are referred toas the active zone. In one aspect of the present invention, the CPU 46is capable of producing a composite video image for simulatedface-to-face contact when the conferencee 36 is located at any point inthe active zone. The CPU 46 is therefore capable of generating thevirtual camera having any number of aspect ratios depending upon thelocation of the conferencee 36 or conferencees within the active zone.

In one embodiment, the intersection point 58 is approximately six inchesaway from the monitor 40. This advantageously allows the videoconferencing system 30 of the present invention to provide the virtualcamera with an aspect ratio suitable for large portrait capture. Thelarge portrait capture produces a relatively narrow and tall field ofview for the resulting virtual camera, which is advantageous indetecting gestural movements on the part of a conferencee disposed inclose proximity to the video monitor 40, such as during desktop videoconferencing. The present invention also has the ability to provide thevirtual camera with an aspect ratio suitable for a large landscapecapture. The large landscape capture produces a relatively wide andshort field of view for the resulting virtual camera, which isadvantageous in viewing the participants of a large or spread out groupof conferencees, such as during room-based video conferencing. As willbe appreciated, the ability to set arbitrary aspect ratios effectivelymaximizes the versatility of the video conferencing system 30 inaccommodating both portrait and landscape capture.

The video conferencing system 30 of the present invention is alsorelatively immune to the parallax distortions that plague prior artvideo conferencing systems. With continued reference to FIG. 4, thisimmunity to parallax distortions is due to the spaced relation betweenthe video cameras 42, 44. The video cameras 42, 44 are disposed oneither side of the video monitor 40 such that video images of the localconferencee 36 may be captured from two separate vantage points. Asnoted above, the CPU 46 thereafter operates to seamlessly combine thevideo images from each of the cameras 42, 44 wherein the resultingcomposite video image depicts the local conferencee 36 looking outwardlyfor face-to-face contact with the remote conferencee. Due to this imagemanipulation, the individual video cameras 42, 44 can maintainrelatively narrow fields-of-view 54, 56 without jeopardizing the CPU's46 ability to produce a meaningful composite video image of the localconferencee 36. It is well known that video cameras having narrowprojection profiles are capable of obtaining video images that arerelatively flat with minimal parallax distortion.

In contrast, the prior art video camera 14 shown in FIG. 5 does notcombine with any other video source and therefore must rely on its ownrelatively wide projection profile 60 to encompass the local conferencee18. Video cameras having wide projection profiles, however, are known toproduce video images having rounded or “fish-eye” parallax distortionsthat oftentimes causes the video images to appear convoluted andunnatural. In light of the foregoing, the narrow fields-of-view 54, 56employed in the present invention minimize the extent of any parallaxdistortion, and thus enable the system to produce and display compositevideo images that are relatively flat and naturalistic in appearance.

With reference to FIG. 6, the video conferencing system 30 of thepresent invention also minimizes parallax distortions by implementing astretching function which makes the composite image 62 appear flatterand more naturalistic. The stretching of the composite image 62 may beperformed under the direction of the video graphics card 48 and/or theCPU 46. For purposes of discussion, the stretching function will beexplained with reference to the video graphics card 48. The videographics card 48 may comprise any number of commercially available videographics cards enabled for device controlled interface (DCI) operation.DCI operation allows the video graphics card 48 to stretch a relativelysmall pixel count image to a full screen pixel count image. The videographics card 48 is thus capable of selectively stretching the compositeimage from an original state (shown in dotted lines at 64) to anexpanded state (shown in solid lines at 66). As can be readilyrecognized, this image-stretching feature further conditions thecomposite video image 62 of the present invention into a flatter andmore natural shape, thereby optimizing the quality of the videocommunication.

The video conferencing system 30 of the present invention can beimplemented in both a room-based conferencing arrangement and a desktopconferencing arrangement. Room-based video conferencing systems includeat least two remotely located conferencing stations communicativelylinked to one another, wherein each conferencing station is designed toaccommodate a plurality of conferencees. A room-based conferencingstation of the present invention may include several large dedicated TVmonitors, at least two image capture devices, a dedicated CPU, a controlbox, and a dedicated cabinet to house the components. Desktop videoconferencing systems also include at least two remotely locatedconferencing stations communicatively linked to one another, whereineach conferencing station is designed to accommodate a limited number (1or 2) conferencees. A desktop conferencing station of the presentinvention may include a standard computer monitor, at least two imagecapture devices, and a computer or processor unit for coordinating thetransmission and receipt of audio and visual information to and from thevarious conferencing stations.

For purposes of discussion, the improved video conferencing system 30 ofthe present invention will be described with reference to the variousdesktop video conferencing stations shown in FIGS. 7-14. The componentscommon to each desktop video conferencing station include a personalcomputer 72, a VGA computer monitor 74, and at least one pair of videocameras 76, 78 disposed about the periphery of the video monitor 74. Thepersonal computer 72 may comprise any of a variety of commerciallyavailable personal computing systems, but should be equipped with avideo conferencing hardware and software system for personal computers,such as the PROSHARE® system manufactured by Intel Corporation. Thehardware within the PROSHARE® system includes the communication link 34,the CPU 46, the video graphics card 48, and the video capture devices50, 52 described above with reference to FIG. 2. The software within thePROSHARE® system coordinates the interactivity of the videoconferencing, as well as the process of seamlessly combining videoimages to produce a composite video image of the local conferencee. Thevideo monitor 74 shown in FIGS. 7, 10, and 13 may include any number ofcommercially available computer monitors, while the video monitors 74shown in FIGS. 8-9, 11-12, and 14 comprise computer monitorsspecifically designed to house the various video cameras 76, 78, 82, 84along the periphery of the monitor 74. The video cameras 76, 78, 82, 84may comprise any number of commercially available cameras capable ofgenerating a video output.

With reference to FIGS. 7-9, the video cameras 76, 78 are disposed in agenerally vertically co-aligned fashion about the periphery of thedisplay screen of the video monitor 74. The CPU (not shown) is capableof forming a composite video image depicting a local conferencee (notshown) looking directly into a camera by seamlessly combining theindividual video images obtained by the vertically co-aligned videocameras 76, 78. The formation of the composite video image causes thepoint of view of each video camera 76, 78 to effectively shift inwardfrom its location along the upper and lower periphery of the videomonitor 74 toward a predetermined location between the video cameras 76,78. This inward shifting continues until the point of view of each videocamera 76, 78 converges together to form a virtual camera at thepredetermined location on the display screen, as shown at 86.

With reference to FIGS. 10-12, the video cameras 76, 78 are disposed ina horizontally co-aligned fashion about the periphery of the displayscreen of the video monitor 74. The CPU (not shown) is capable ofseamlessly combining the individual video images obtained by thehorizontally disposed video cameras 76, 78 to once again form acomposite video image depicting a local conferencee (not shown) lookingdirectly into a camera for simulated line-of-sight image capture. Theformation of the composite video image causes the point of view of eachvideo camera 76, 78 to effectively shift inward from its location alonga respective side of the video monitor 74 toward a predeterminedlocation between the video cameras 76, 78. The shifting continues untilthe point of view of each video camera 76, 78 converges together to forma virtual camera at the predetermined location on the display screen, asat 86.

With reference to FIGS. 13 and 14, the first pair of video cameras 76,78 is generally horizontally co-aligned about either side of the videomonitor 74 and a second pair of video cameras 82, 84 is provided in agenerally vertically co-aligned fashion about the upper and lowerperiphery of the video monitor 74. In this embodiment, the CPU (notshown) is capable of seamlessly combining the individual video imagesobtained by the video cameras 76, 78, 82, 84 to form a composite videoimage depicting a local conference (not shown) looking directly into acamera. The formation of the composite video image causes the point ofview of each video camera 76, 78, 82, 84 to effectively shift inwardfrom its location along a respective side of the video monitor 74 towarda predetermined location between the video cameras 76, 78, 82, 84. Theshifting continues until the point of view of each video camera 76, 78,82, 84 converges together to form a virtual camera at the predeterminedlocation on the display screen, as at 86.

In one aspect of the present invention, the composite video imagecreated in each of the foregoing embodiments of the video conferencingsystem 30 should be formed such that the resulting virtual camera 86 isgenerally co-aligned with the displayed image of the remote conferencee36. In this fashion, the local conferencee 36 will appear to be lookingdirectly into the virtual camera 86, which, in turn, results insimulated face-to-face contact between the conferencees 36 for improvedinterpersonal communication.

The improved video conferencing system 30 of the present inventionovercomes various deficiencies found in prior art video conferencingsystems. The video conferencing system 30 provides improved face-to-facecontact between conferencees by providing a virtual camera for simulatedline-of-sight image capture. The conferencing system 30 accomplishesthis without reconfiguring the video conferencing stations withadditional optical components for modifying the transmission and/ordisplay of remote video images. The conferencing system 30 provides theability to vary the aspect ratio of the video cameras employed in eachvideo conferencing station, thereby allowing the video conferencingsystem 30 to adapt to a change in the position of the local conferenceewithout causing distorted and unnatural appearing video images when thelocal conferencee moves outside the preferred aspect ratio supported bythe video camera. The video conferencing system 30 also advantageouslyreduces the degree of parallax or “fish-eye” distortions when the localconferencee is disposed relatively close to the monitor, therebyproviding a more naturalistic image of the conferencees for improvedinterpersonal communication.

It is to be readily understood that the foregoing video conferencingembodiments shown in FIGS. 3-14 are set forth by way of illustrationonly and are not to be deemed exhaustive as to the scope of the presentinvention. The virtual camera technique of the present invention mayfind use in any number of computer-based image capture applicationswhere line-of-sight image capture is desired, including but not limitedto video conferencing, video postcards, video messaging, multimediatraining, and multimedia authoring. As used herein, the term“computer-based” is to be construed broadly as including any of avariety of microprocessor-based systems regardless of the physicalhousing or structure. For example, a computer-based image capture systemof the present invention may take the form of a kiosk having aninternally disposed processing unit, a display, and at least two imagecapture devices for capturing images of an operator from at least twooffset locations. It is furthermore to be understood that the imagecapture devices employed as part of the present invention may compriseany number of image capture devices capable of obtaining photographicand/or video images.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described in detail. It shouldbe understood, however, that the description herein of specificembodiments is not intended to limit the invention to the particularforms disclosed, but on the contrary, the invention is to cover allmodifications, equivalents, and alternative falling within the spiritand scope of the invention as defined by the appended claims.

What is claimed is:
 1. An apparatus, comprising: a display device todisplay information; first and second image capture devices disposedproximate to said display device to capture first and second images of aperson within a field of view from a first and a second offset location;and a control to select an aspect ratio from a portrait aspect ratio anda landscape aspect ratio, to process the first and second images as datafor imaging to form a virtual camera at a predetermined location on saiddisplay device for simulated line-of-sight capture of said person in thefield of view at said selected aspect ratio and further to implement astretching function on the simulated line-of-sight capture of saidperson.
 2. The apparatus as set forth in claim 1, wherein said firstimage capture device is to capture images at a first position offsetfrom said person, and said second image capture device is to captureimages at a second position offset from said person.
 3. The apparatus asset forth in claim 2, wherein said first image capture device isdisposed proximate to a top portion of said display device, and saidsecond image capture device is disposed proximate to a bottom portion ofsaid display device.
 4. The apparatus as set forth in claim 2, whereinsaid first image capture device is disposed proximate to a first lateralside of said display device, and said second image capture device isdisposed proximate to a second lateral side of said display device.
 5. Acomputer system for use in simulating image capture, comprising: adisplay to display information; at least two cameras disposed proximateto said display, said cameras for capturing images of a person within afield of view from different offset locations; and a processor coupledto said cameras for processing said images as data and combining saidimages to form a composite image having an aspect ratio selected from aportrait aspect ratio and a landscape aspect ratio, and to implement astretching function on the composite image.
 6. The computer system asset forth in claim 5, wherein said cameras includes a first camera and asecond camera, said first camera to capture images at a first positionoffset from said person, and said second camera to capture images at asecond position offset from said person.
 7. The computer system as setforth in claim 6, wherein said first camera is disposed proximate to atop portion of said display and said second camera is disposed proximateto a bottom portion of said display.
 8. The computer system as set forthin claim 6, wherein said first camera is disposed proximate to a firstlateral side of said display, and said second camera is disposedproximate to a second lateral side of said display.
 9. The computersystem as set forth in claim 8, wherein said cameras further include athird camera and a fourth camera, said third camera to capture images ata third position offset from said person, and said fourth camera tocapture images at a fourth position offset from said person, whereinsaid third camera is disposed proximate to a top portion of saiddisplay, said fourth camera is disposed proximate to a bottom portion ofsaid display, said processor combining the first, second, third, andfourth images to form said composite image.
 10. A method of simulatingimage capture within a computer-based image capture system, comprising:selecting an aspect ratio for a composite image from a portrait aspectratio and a landscape aspect ratio; capturing a first image of an objectfrom a first predetermined location; capturing a second image of saidobject from a second predetermined location offset from said firstpredetermined location; and processing said first and second images ofsaid object as imaged data to form a composite image having saidselected aspect ratio and depicting said object looking directly into alens of a camera, and to implement a stretching function on thecomposite image.
 11. The method set forth in claim 10 further comprisingdisplaying said composite image on a display.
 12. The method set forthin claim 10 further comprising transmitting said composite image fordisplay at a remote location.
 13. A conferencing station comprising: adisplay to view a first conferee at another location; two camerasdisposed proximate to said display at different offset locations tocapture images of a second conferee within a field of view from saiddifferent offset locations of said cameras; and a processor coupled toreceive image data from said cameras to process images and combine saidimages to form a composite image of the second conferee lookingsubstantially directly into a lens of a camera when viewed by the firstconferee, and to implement a stretching function on the composite image,wherein the composite image has an aspect ratio selected from a portraitaspect ratio and a landscape aspect ratio available in the conferencingstation.
 14. The conferencing station as set forth in claim 13, whereinsaid two cameras comprise a first camera and a second camera, said firstand second cameras being disposed on opposite sides of the display fromeach other.
 15. The conferencing station as set forth in claim 14,wherein said first camera is disposed proximate to a top portion of saiddisplay, and said second camera is disposed proximate to a bottomportion of said display.
 16. The conferencing station as set forth inclaim 14, wherein said two cameras comprise a third camera and a fourthcamera, said third and fourth cameras being disposed on opposite sidesof the display from each other and offset from the first and secondcameras, wherein said processor combines images from the first,second,third, and fourth cameras to form the composite image.
 17. Theconferencing station as set forth in claim 16, wherein said first camerais disposed proximate to a top portion of said display, said secondcamera is disposed proximate to a bottom portion of said display, saidthird camera is disposed proximate to a first lateral side of saiddisplay and said fourth camera is disposed proximate to a second lateralside of said display.
 18. A method of facilitating face-to-facecommunication between a first conferee and a second conferee,comprising: selecting an aspect ratio for a composite image from aportrait aspect ratio and a landscape aspect ratio; capturing a firstimage of a first conferee from a first predetermined location; capturinga second image of the first conferee from a second predeterminedlocation offset from said first predetermined location; and processingsaid first and second images of the first conferee as imaged data toform a composite image having the selected aspect ratio and depictingthe first conferee looking directly into a lens of a camera so as to beappearing to look straight in the eye of the second conferee when viewedby the second conferee and to implement a stretching function on thecomposite image.
 19. The method of claim 18, wherein: capturing a firstimage comprises capturing a first image from a first location proximatea top of a display device; and capturing a second image comprisescapturing a second image from a second location proximate a bottom ofthe display device.